Channa Asela

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1 Reproducing the following contents by amending or deleting the author s name and contact numbers is prohibited. You may or print without any amendment. Underline the most suitable answer 1995-I-2 Two empty balloons of equal weight are filled with two gasses A & B till their volumes are the same. If A is air, which of the gasses listed below would be B? (1) Helium (2) Hydrogen (3) Carbon dioxide (4) Oxygen A B 1995-I-5 Which gas will be liberated as bubbles when a bottle of soda is opened? (1) Oxygen (2) Carbon dioxide (3) Nitrogen (4) Hydrogen 1995-I-7 Bonds between atoms are formed between (1) the nuclei (2) the electrons (3) the protons (4) the neutrons 1995-I-12 Which of the elements indicated below are isotopes? Element number of neutrons mass number A B C D (1) A & B (2) B & D (3) A & D (4) A & C 1995-I-35 If the atomic number of the element X is 12, what is the formula of its Bromide? (1) XBr (2) X 2 Br (3) X 2 Br 2 (4) XBr 2 Page : 1

2 1996-I-2 Which of the following compound contains a dative bond? (1) CO 2 (2) NaCl (3) NH 4 CL (4) H 2 O 1996-I-5 The chemical formula for quick lime is (1) CaCO 3 (2) CaO (3) Ca(OH) 2 (4) CaSO I-6 The valency of the element X is 5. Which of the following is likely to be the formula of its oxide? (1) XO 5 (2) X 5 O (3) X 2 O 5 (4) X 5 O I-10 Which of the following compounds when heated will give out oxygen as a product? (1) K 2 CO 3 (2) KNO 3 (3) MgCO 3 (4) KNO I-11 The mass number of an element is 36. There are 19 neutrons in its nucleus. This element is (1) a monovalent non-metal (2) a bivalent non-metal (3) a monovalent metal (4) an inert gas 1996-I-13 Shown here are the symbols of several elements of a period in the periodic table Li, Be, B, C, N, O, F An increase in which characteristic below is seen, as you proceed from left to right, along this period (1) atomic radius (2) metallic property (3) ionization energy (4) reducing property 1996-I-15 The following gases are collected in four boiling tubes (a) ammonia (b) chlorine (c) carbon dioxide (4) hydrogen In which tube/tubes will a wet piece of red litmus turn blue? (1) A & B (2) B & C (3) A only (4) D only Page : 2

3 1996-I-18 The mass number of an atom of the element X is 39. Its atomic number is 19. Which of the following statements are correct, regarding this element? (A) the number of protons contain in an atom X is 19 (B) the number of neutrons contained in an atom of X is 39 (C) the number of electrons contained in an atom of X is 39 (D) The number of neutrons contained in an atom X is 20 (1) only A and B are correct (2) only B and C are correct (3) only C and D are correct (4) only A and D are correct 1996-I-39 The number of electrons of which of the following ions, is equivalent to the number of electrons of the chloride ion (Cl - )? (1) Na + (2) K + (3) O 2- (4) Mg I-3 In which of the following ranges of numbers does the number of elements that have been discovered so far. (1) (2) (3) (4) I-9 The modern periodic table is based on the feature, (1) mass number (2) atomic number (3) atomic volume (4) electronic configuration 1999-I-9 The modern periodic table is based on the feature, (1) mass number (2) atomic number (3) atomic volume (4) electronic configuration Page : 3

4 1997-I-21, 23 Questions numbers 21 & 23 are based on the following information The electronic configurations of four elements identified as A, B, C, D are given below. Element Electronic configuration A 2,8 B 2,8,1 C 2,8,7 D 2,8,8 21. The element in group VII of the periodic table is 23. The element with the highest ionization energy is 1998-I-3 To which group in the periodic table does the element that the electronic configuration 2,8,1 belong? (1) Group I (2) Group II (3) Group III (4) Group IV 1998-I-6 Which of the following substance is present in the well water, but not present in rain water? (1) Oxygen (2) Carbon dioxide (3) Minerals (4) Sulphur dioxide 1998-I-9 Which of the following gives a gaseous product when heated? (1) Calcium Carbonate (2) Magnesium Oxide (3) Sodium Carbonate (4) Sodium Chloride Page : 4

5 1998-I-17, 18 and 19 Questions 17, 18 and 19 are based on the following information The properties of four elements which have been identified as A, B, C, D (where A, B, C, and D are not their true symbols) are stated in the following table. Substance Melting Point C Boiling point C Ability to conduct electricity under normal conditions A Weak B Weak C Weak D Strong 17. The element which exists as a gas at room temperature is 18. The element which has the possibility of being copper is 19. The element which is likely to form an ionic compound with chlorine is 1998-I-31 Out of chemical equations A, B, C and D given below, which ones are the balanced equations? (A) CaCO 3 CaO + CO 2 (C) Zn + 2 HCl ZnCl 2 + H 2 (B) C 6 H 12 O 6 + O 2 CO 2 + H 2 O (D) NaOH + H 2 SO 4 Na 2 SO 4 + H 2 O (1) A and B (2) A and C (3) B and D (4) C and D Page : 5

6 The number of protons (p), electrons (e) and neutrons (n) contained in an atom of the two varieties X and Y are stated in the table below. p e n X Y Which of the following, regarding X and Y, is correct? (1) X is a cation (2) Y is an anion (3) Y has greater mass than X (4) X and Y are different elements 1999-I-12 Elements contained in glucose are (1) C and H (2) C, H and O (3) C, H and N (4) C, H, O and N 1999-I-13 Elements contained in limestone, marble, quick lime and slaked lime is (1) carbon (2) calcium (3) hydrogen (4) potassium 1999-I-14 Four substances used in houses are given below as A, B, C and D (A) Lime juice (B) Baking soda (C) Lime (D) Vinegar The substances that are acidic among these are (1) A and C (2) A and D (3) A and B (4) C and D 1999-I-17 Which of the following gases cannot be considered as a rare gas? (1) Helium (2) Argon (3) Nitrogen (4) Neon Page : 6

7 1999-I-19 The number of electrons of fluoride ion (F - ) is equal to the number of electrons of which the following ions A, B, C and D? (The atomic numbers of the elements oxygen, fluorine, sodium, chlorine and calcium are 8, 9, 11, 17, 20 respectively). (A) O 2- (B) Na + (C) Ca 2+ (D) Cl - (1) A and B (2) B and C (3) C and D (4) A and D 1999-I-20 Which of the following chemical equations A, B, C and D are balanced equations? (A) CaCO 3 CaO + CO 2 (B) NaOH + HCl NaCl + H 2 O (C) KMnO 4 K 2 MnO 4 + MnO 2 + O 2 (D) Mg + H 2 SO 4 MgSO 4 + H 2 (1) A and B (2) A, B and C (3) A, B and D (4) C and D 1999-I-21 What is the chemical formula of the compound referred to as caustic soda? (1) NaCl (2) NaOH (3) KOH (4) KCl 1999-I-22 (diagram) H Li X A part of the periodic table is shown in the diagram. Which of the following statements about the element X is true? (X is not the real symbol of the element) (1) X is an element which is less reactive (2) X is a metal (3) X is highly reactive element (4) There are two electrons in the outer most shell of atom X Page : 7

8 1999-I-7 A apart of the periodic table is given here. Which one of the following is correct regarding the elements A, B, C and D? [A, B, C and D are not the standard symbols of these elements] I A B D II C A part of the periodic table is given here. Which one of the following is correct regarding the elements A, B, C, D? [A, B, C, D ar not the standard symbols of these elements] (1) A is an inert gas (2) Metallic properties of C are more than those of B (3) An ionic compound is formed between c and D 1999-I-15 Which of the following substances when heated evolve gaseous product? (A) Potassium nitrate (C) Sodium carbonate (B) Lead nitrate (D) Copper carbonate (1) A, B and C (2) A, B and D (3) B, C and D (4) A, C and D 1999-I-29 Which solution given below has a ph value of 7? (1) ammonium solution (2) lime juice (3) vinegar (4) common salt 2000-I-11 An element that exists naturally as a monatomic gas is (1) oxygen (2) hydrogen (3) helium (4) nitrogen 2000-I-12 Which of the following oxides forms an acidic solution when mixed with water? (1) MgO (2) NO 2 (3) Na 2 O (4) Fe 2 O 3 Page : 8

9 2000-I-17 The acid which is present in vinegar is (1) acetic acid (2) citric acid (3) lactic acid (4) hydrochloric acid 2000-I-18 What is the chemical formula of quick lime? (1) CaO (2) Ca(OH) 2 (3) CaSO 4 (4) CaCO II-5(i) H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K A part of the periodic table is shown below. (a) Write the name of the element with the atomic number 6 (b) What is the chemical symbol of the element has the electronic configuration of 2,8,3? (c) What is the element present in the second group fifth group, second period? (d) Out of the elements given in the table, which element forms positive ions most easily? (e) Give an element which forms an acidic oxide 2000-I-3 Which gas causes damage to the ozone layer of the atmosphere? (1) Carbon dioxide (2) Methane (3) Nitrogen dioxide (4) Chloro fluoro carbon 2000-I-5 A gas responsible for acid rain is (1) sulphur dioxide (2) carbon dioxide (3) carbon monoxide (4) nitrous oxide Page : 9

10 2000-I-17 In the atoms of two elements found in the same period of the periodic table, (1) number of electrons is equal (2) number of protons is equal (3) number of neutrons is equal (4) number of energy levels is equal 2000-I-20 Atomic species Number of Protons Number of Electrons Number of Neutrons X Y Three statements regarding the above X and Y atomic species are given below (A) the atomic numbers of X and Y are equal (B) the atomic weights of X and Y are equal (C) the electronic configurations of X and Y are equal Out of the statement, the correct one/ones is/are (1) A only (2) B only (3) C only (4) A and C only 2000-I-25 ph value could be 1 in, (1) a solution of lime water (2) a solution of sodium chloride (3) distilled water (4) a solution of hydrochloric acid Page : 10

11 2000-I-26, 27 & 28 The table below shows some properties of the substances A, B, C and D. Based on this, answer the question numbers 26 to 28 Substance Melting Point C Solubility in water Ability to conduct electricity under normal conditions & when fused A B C D insoluble insoluble insoluble soluble weak weak conducts conducts 26) Which one is most likely to be a metallic element? 27) Which one could be a simple molecular, covalent compound? 28) Which one is most likely to be an ionic compound? 2001-I-6 Which of the following metals, can exist as element in nature? (1) Sodium (2) Iron (3) Silver (4) Zinc 2001-I-21 The atomic number of an element is 19. The number of electrons in its outer most energy level is (1) 1 (2) 9 (3) 18 (4) 19 Page : 11

12 2001-I-22 Select the group which comprises of two liquids that conduct electricity and one liquid that does not conduct electricity (1) sugar solution, distilled water, acid solution (2) sugar solution, salt solution, distilled water (3) sugar solution, salt solution, acid solution (4) distilled water, acid solution, sugar solution 2001-I-23 The lime stone, which is used in the production of lime locally is (1) calcium oxide (2) calcium carbonate (3) calcium phosphate (4) calcium sulphate 2001-I-31 Following are several statements, associated with ionic compounds (a) an ionic bond is formed by sharing a pair of electrons between two atoms (b) compounds with ionic bonds, possess the ability of conducting electricity (c) there are positive and negative ions in compounds with ionic bonds (d) compounds with ionic bonds have low melting points and boiling points The correct statements out of the above are (1) a and b (2) b and c (3) c and d (3) a and d 2001-I-34 Four statements related to elements are given below (a) an element, when heated, decomposes into simple substances (b) the melting point of pure substance, always has a fixed value (c) the mass of a neutron is equal to that of a proton (d) the number of neutrons in the nucleus of an atom, is the atomic number of that element The correct statements out of the above are (1) only a and b (2) only b and c (3) only c and d (4) only a and d Page : 12

13 2001-I-37 Four statements made by a student regarding the element X are given below. Which one is the correct statement? (1) the atomic number is 40 (2) the mass number is 18 (3) there are 40 electrons, out side the nucleus (4) there are 18 protons in the nucleus 2001-I-39 When a negatively charged rod is brought closer to a positively charged gold-leaf electroscope, the change observed in gold leaves, at once would be (1) that the leaves which were already divergent get diverged further (2) that the leaves which were already divergent reduce the divergence (3) that there is no change in the divergence of the leaves (4) that the leaves which were in the convergent position, get diverged 2002-I-4 What is the chemical formula for quick lime? (1) CaSO 4 (2) CaO (3) Ca(OH) 2 (4) CaCO I-8 Which of the following is the neutral solution? (1) Solution of ammonia (2) Solution of sugar (3) Solution of vinegar (4) Solution of soap 2002-I-10 A student has written the chemical formulae of several oxides in the following way. Which of them is erroneously written? (1) CaO (2) CO 2 (3) SO 3 (4) NaO 2002-I-13 Which of the following is incorrect regarding the element sodium? (1) Chemical formula of its hydride is NaH (2) Chemical formula of its chloride is NaCl (3) Its reaction with oxygen is very strong (4) Its reaction with water is very waek Page : 13

14 2002-I-14 The element X, forms an ion in the form X 2+. Number of electrons, equal to the number of electrons in that ion is contained in (1) Na + (2) K + (3) F - (4) Al I-20 Which gas covers the maximum percentage in volume of sample of air taken from the atmosphere around us? (1) Oxygen (2) Carbon-dioxide (3) Nitrogen (4) Water vapour 2002-I-27 Which of the following element exist in nature as di-atomic molecule? (1) Sodium (2) Argon (3) Oxygen (4) Sulphur 2002-II-5 B C D A E F G The following is a part of the Periodic Table. Using the elements given from A to G answer the questions given below. (Take note that A to G are not the real symbols of the related elements.) From the elements A to G given in the table (a) What is the most electrically negative element? (b) What is the element that is least reactive? (c) What are the two elements between which an ionic bond could be easily built? (d) What are non-metallic elements present? (e) What is the element that has the highest first ionization energy? 2002-I-28 Which has given below exists as a monatomic molecule? (1) Hydrogen (2) Chlorine (3) Argon (4) Nitrogen Page : 14

15 2002-I-31 Following are some features stated about the element X (a) Its mass number is 63 (b) Its atomic number is 63 (c) The number of neutrons in its atom is 29 (d) The number of electrons in its atom is 29 Which of the above statements are correct? (1) a and c only (2) b and c only (3) a and d only (4) b and d only 2002-I-32 Some statements put forward by a group of students about the patterns of the periodic table given below. (a) The melting points of elements first increase and then decrease when moving from left to right. (b) Elements with metallic properties are found on the left and those with non metallic properties are found on the right side (c) There is a certain relationship between the valency of an element and the number of the group to which it belongs (d) The boiling point increases when going down any of the groups The correct statements out of these are (1) a, b and c only (2) b, c and d only (3) a, b and d only (4) a, c and d only 2002-I-33 According to the data given in the table below about the compounds A, B, C and D which one exists as a liquid at room temperature? Compounds Melting point C Boiling point C A B C D Page : 15

16 2002-I-34 The number of electrons in the atom of a certain element is 20. Its relative atomic mass is 40. Select the correct statements about this element from those given below. (a) This element belongs to Group 2 of the Periodic Table (b) This element belongs to the 2 nd Period of the Periodic Table (c) This element can form ionic compounds (1) only a and b (2) only b and c (3) only a and c (d) all a, b and c The questions number 35 and number 36 are based on the equation given below. x Al + y H 2 O Al 2 O 3 + z H I-35. The correct values for x, y, and z in the above equation are (1) 2, 3, 3 (2) 3, 3, 2 (3) 2, 1, 2 (4) 1, 2, I-36. According to the formulae of the compounds in the above equation, the valencies of the aluminum, oxygen and hydrogen respectively are (1) 3, 2, 1 (2) 2, 3, 1 (3) 1, 2, 2 (4) 2, 1, I-14 There are 11 protons and 12 neutrons in an atom of the element sodium. In which response do you get the atomic number and mass number of sodium stated in the standard way? (1) Na (2) Na (3) Na (4) Na 2003-I-16 Magnesium oxide is formed when magnesium is burnt in air. The correct balanced chemical equation, which represents this reaction, is (1) Mg + O 2 MgO 2 (2) Mg 2 + O 2 2MgO (3) Mg + O 2 MgO (4) 2Mg + O 2 2MgO Page : 16

17 Questions from No 17 to 19 are based on the following table. Study properties of the substances indicated as A, B, C, D, E in the table and answer the questions given below. (A, B, C, D and E do not denote the standard symbols or formulae of the substances) Substance Melting Point Boling Point Conduct of Electricity C C In solid state In fused state A B C D E weak weak weak high weak weak weak high high weak 2001-I-17 Which substance exists as a liquid at room temperature? 2001-I-18 Which substance could be an ionic compound? (1) B (2) C (3) D (4) E 2001-I-19 Which substance shows properties similar to those of copper? (1) B (2) C (3) D (4) E 28-I-28 Several proposals put forward to minimize the air pollution due to combustion of fuel in vehicles are stated below. A to encourage the use of bicycles B to implant a motor-boat transport service, in place of the prevailing transport services C to prevent from running vehicles which do not have proper combustion system Which of the above are the most eco-friendly and practicable proposals? (1) A,B,C only (2) A, C, D only (3) B, C, D only (4) A, B, D only Page : 17

18 2003-II-5 Matter is made up of elements. The building unit of all elements is the atom. Atoms of various elements differ from one another. Their chemical and physical properties too, differ from each other. (a) Write down the electronic configuration of the element of atomic number 12 (b) State the change that takes place in electronic configuration when a stable ion is formed by the element stated in (a) above (c) State the period and group to which the above mentioned element belongs to in the periodic table (d) State one property expected of this element, based on its position in the periodic table. (i) Sodium and aluminium are two metals found in the laboratory. (a) The metal sodium is stored in paraffin oil in the laboratory. Explain the reason for this. (b) Vessels made of aluminium are often used in the cooking of food. But if aluminium enters the body, aluminium poisoning occurs. It is thought that although aluminium vessels are used in cooking, aluminium does not mix into the food. Explain why it can be assumed that aluminium does not mix with food. (c) State one factor that should be considered when using aluminium vessels, to prevent food poisoning I-1 Which of the following is the lightest gas? (1) Nitrogen (2) Oxygen (3) Carbon dioxide (4) Helium 2004-I-2 A monatomic gas is (1) Nitrogen (2) Hydrogen (3) Helium (4) Oxygen Questions from number 19 to number 21 are based on the following table which gives the numbers of the protons, neutrons and electrons in particles A, B, C, D and E Particles No. of protons No of neutrons No of electrons A B C D E Page : 18

19 2004-I-19 The isotopes are (1) A and B (2) A, B and C (3) D and E (4) A, B, C and D 2004-I-20 A positive ion is 2004-I-21 The neutral particle / particles is / are (1) B only (2) D only (3) B and D only (4) B, D and E only 2004-II-5 The periodic table and the activity series are two ways of classifying elements. A rough sketch of a portion of the periodic table and a portion of the activity series are given below in the diagram 1 an diagram 2 respectively. (A) Three elements situated at three places in the periodic table are shown below by symbols A, B, and C (A, B, and C are not their real symbols) A 18B 19 20C Diagram-1 (i) (ii) (iii) (iv) (v) (vi) Write the electronic configuration of element A Write a characteristic specific to the group to which the element B belongs Write respectively the period and the group to which the element C belongs in the periodic table. Write the formula of the compound formed between the to elements A and C State the changes taking place in the electronic configurations of each of the elements A and C when a compound is formed between them State one use of classifying elements in the form of Periodic table Page : 19